What, if anything, is a "Tyrannosaurus rex"?

Leonard Finkelman

Paleontologists distinguish between fossils preserving the remains of organisms (body
fossils) and fossils preserving evidence of an organism’s activities (trace fossils).
As with extant organisms, the naming of body fossil species is guided by principles
consistent with a descriptive theory of names. By contrast, the naming of trace fossil
species is explicitly guided by the causal theory of naming. Consequently, paleontologists
conventionally maintain a strict distinction between body fossil and trace fossil
nomenclatures.

I argue that metaphysical and semantical considerations undermine conventional justification
for distinct nomenclatures. Body fossils are materially and causally more similar
to traces than they are to living organisms. The names of body fossil species and
trace fossil species play the same role in paleontological theories. If convention
is maintained, then theorists must admit that a nomenclature including both extant
and fossil species is metaphysically heterogeneous. If convention is revised or rejected,
then theorists must admit that fossil nomenclature has no single consistent foundation
in semantic theory. Paleontologists are therefore left with a choice between one kind
of theoretical discordance or another.